Removal of ammonium from greywater using natural zeolite

► Natural zeolite was used to remove ammonium. ► The natural zeolite shows good performance for ammonium removal with up to 97%. ► The performance depends on the contact time, zeolite loading, initial ammonium concentration and pH. ► The adsorption kinetics is best approximated by the pseudo-second-order model. ► Freundlich model provides the best fit for the adsorption isotherm result.